Ian McKellen has added Sir Arthur Conan Doyle’s uncanny sleuth to his list of literary incarnations, having agreed to play Holmes in director Bill Condon’s upcoming film A Slight Trick of the Mind.

In A Slight Trick of the Mind, the 74-year-old will, obviously, play Holmes in his later years. And this version was not penned by Conan Doyle, but is instead adapted from a 2006 novel by Mitch Cullin.

The story picks up with the detective at age 93, long-ago retired to the rural area of Sussex, where he is haunted by an unresolved case from a half-century ago.

His partner, Dr. Watson, is no longer with him. And his mental acuity has bid him farewell, too. This is a Sherlock Holmes grappling with his own faded and tattered memory, whose powers of observation and deduction are not what they used to be.

It’s the first time McKellen and Condon have worked together since 1998’s Gods and Monsters, which earned McKellen a Best Actor Oscar nod for his performances as Bride of Frankenstein director James Whale, and won Condon the Best Adapted Screenplay award.

Cullin’s novel Tideland was previously adapted by director Terry Gilliam, and the script for A Slight Trick will be written by Jeffrey Hatcher (Casanova, Stage Beauty.)

Other authors have also explored Holmes’ twilight days after Conan Doyle deposited him in the happily-ever-after of retirement.

In 1994, Laurie R. King’s The Beekeeper’s Apprenticeintroduced a 15-year-old American orphan girl who hones her own detective skills under the tutelage of Holmes when he was slightly younger, in 1915 during the start of World War I. The “Mary Russell series” has since spawned 12 books, with more on the way.

Graham Moore’s 2011 novel The Sherlockiantold dueling stories — one set in the present day as a young, literary enthusiast and Holmes fan seeks to solve a murder, and another detailing the mysterious events that led Conan Doyle to resurrect his most famous creation after killing him at Reichenbach Falls in the 1893 tale The Final Problem.

And, of course, McKellen’s older detective will arrive in the formidable shadow of Benedict Cumberbatch’s young, contemporary Holmes in the insanely popular BBC One series Sherlock.

Coincidentally, Cumberbatch is currently at the Toronto International Film Festival to premiere the Wikileaks drama The Fifth Estate, which is directed by … Condon, of course.